diff --git a/sass/init/_variables.scss b/sass/init/_variables.scss
index 56045f4..4dac7ae 100644
--- a/sass/init/_variables.scss
+++ b/sass/init/_variables.scss
@@ -167,6 +167,10 @@ $rem-fallback:      false;
 //
 // Style guide: sass.variables.zen-grids
 
+// The max content width (the gutters with will be added).
+$max-content-width: 1140px;
+$max-no-sidebars-content-width: 840px;
+
 // These are needed for all breakpoints on all layouts.
 $zen-auto-include-grid-item-base: false;
 $zen-box-sizing: universal-border-box;
diff --git a/sass/layouts/layout-center/_layout-center.scss b/sass/layouts/layout-center/_layout-center.scss
index 846a321..226526b 100644
--- a/sass/layouts/layout-center/_layout-center.scss
+++ b/sass/layouts/layout-center/_layout-center.scss
@@ -32,8 +32,11 @@
   // We wrap the max-width declaration with zen-layout() so we can see the value
   // of $zen-gutters when it is at the larger "xl"-sized media query.
   @include zen-layout(xl) {
-    // The max content width is 1140px (the container width minus the gutters.)
-    max-width: 1140px + $zen-gutters;
+    max-width: $max-content-width + $zen-gutters;
+
+    .no-sidebars & {
+      max-width: $max-no-sidebars-content-width + $zen-gutters;
+    }
   }
 
   @include zen-respond-to(m) {